Tenter dryers



July 14, 1959 J. R. THYGESON, SR

TENTER DRYERS 4 Sheets-Sheet 2 Filed May 3, 1957 oooo FIEL? INVENTOR: JOHN R, THYGESON 5R.

AT'TYS.

July 14, 1959 J. RTI-IYGESON, SR 2,894,334

TENTER DRYERS Filed May 3, 1957 4 Sheets-Sheet 5 F IELL INVENTORZ JOHN R. THYGESON SR.

E# f ATTYs.

July 14, 1959 J. R. THYGESON, SR 2,894,334

TENTER DRYERS l Filed May I5. 1957 4 sheets-sheet 4 FIEEI.

,ATTYS.

mwen-ron'. JOHN R.THYGESON SR.

United States lPatent TENTER DRYERS John R. Thygeson, Sr., Abington Township, Montgomery County, Pa., assignor to Proctor & Schwartz, Inc., Philadelphia, Pa., a corporation of Pennsylvania Application May 3, 1957, Serial No. 656,839

4 Claims. (Cl. 34-158) The present invention relates to tenter dryers, and more particularly to a novel construction of the air distribution nozzles for such dryers.

In tenter dryers, the continuous length of web material is conveyed through the dryers by tenter elements, either tenter clips or tenter pins, which engage the selvages or lateral edges of the web and slide longitudinally through the dryer on chain rails along opposite sides of the dryer housing. The two chain rails are mounted for transverse adjustment within predetermined limits in order to accommodate various widths of cloth that may be dried in the same dryer housing. The chain rails may be disposed parallel to one another, or may be adjusted to converge or diverge at various angles depending on the character of the web material being dried. For example, when drying knit goods, the distance between the chain rails gradually increases from the entrance end to the exit end of the dryer. The conventional tenter dryer affords adjustment of the rails between maximum and minimum spacing in which the minimum spacing is approximately 39% of the maximum spacing between the side rails.

To eifect drying of the web as it is advanced through the dryer by the elements on the chain rails, nozzles are positioned above and below the run of the web through the dryer to direct hot gaseous drying medium against the web. In conventional installations, the nozzles are xed in the housing and extend across the maximum width of the dryer between the chain rails. In order to afford adjustment of the chain rails, the nozzles are spaced above and below the run of the web material a distance suicient to clear the rails and tenter elements when they are adjusted for minimum spacing. In such installations, the clearancebetween the web and the nozzles is at least three inches. It is desirable to maintain the clearance at a minimum in order to obtain the maximum effective drying rate of the web material. Inaddition, when the rails are adjusted toward their minimum spacing, a substantial portion of the drying medium is directed into the space beyond the inwardly adjusted rails. Thus, a substantial portion of the drying medium is doing no useful work. The excess drying medium beyond the contines of the web also tends to dry the outer wedges of the web more rapidly than the central portion, thereby setting up undesirable stresses in the web which tend to deform the web appreciably. This excess air also tends to cause rippling of the web which aggravates the Weave deformation.

With the foregoing in mind, the present invention contemplates a tenter dryer which has increased eiciency over the emciency of conventional dryers.

More specifically, the invention provides a dryer in which the nozzles are set closely adjacent the web being processed.

Another object of the present invention is to provide a tenter dryer in which the nozzles for the drying medium are mounted for adjustment with the side rails, so that the drying medium directed beyond the web is reduced 2 to a minimum, thereby effecting maximum utilization of the drying medium.

The invention also insures uniform distribution of the drying medium across the adjusted width of the chain rails so that when smaller widths of web material are being dried, an increased velocity of drying meditun is obtained, thereby atfording an increase in the rate of advance of the web material through the dryer.

The invention also provides a novel tenter dryer of simplified construction which is fully effective in operation and use.

All of the objects of the present invention and the various features and details of the construction and operation thereof are more fully set forth hereinafter with reference to the accompanying drawings, in which:

Fig. l is a side elevational view of a tenter dryer made in accordance with the present invention. with a portion of the housing broken away to illustrate the arrangement of nozzles therein;

Fig. 2 is a transverse sectional View taken on line 2-2 of Fig. l;

Fig. 3 is a transverse vertical sectional view through the dryer housing taken on line 3 3 of Fig. l;

Fig. 4 is an enlarged fragmentary sectional view taken on the line 4--4 of Fig. 2;

Figs. 5 and 6 are enlarged fragmentary sectional views illustrating the details of the attachment of the nozzles to the chain rail;

Fig. 7 is an enlarged section through an upper nozzle and taken on line '7-7 of Fig. 4;

Fig. 8 is a fragmentary sectional view taken on line 8 8 of Fig. 3 with portions broken away to more clearly illustrate the operation of the present invention; and,

Fig. 9 is a detached perspective View of an `upper nozzle box.

Referring now to the drawings, the dryer comprises a housing lil having mounted therein a pair of chain rails lll, ll. The chain rails ll, ll are mounted on posts l2 which are adjustable laterally in the housing to vary the spacing between the chain rails l1, 11. The chain rails 11 slidably mount tenter elements 13 for gripping the web material W and conveying it through the housing between the chain rails. ln the illustrated embodiment of the invention, the elements 13 comprise tenter clips which are advanced through the housing by chain links i4. The return run of the tenter clips and chain is indicated at 13 and 14.

In accordance with the invention, nozzles are provided in the housing to direct drying medium against the web W. The nozzles are positioned intermediate the chain. rails 1l, lll and are adjustable with the chain rails to extend across the full distance therebetween. To provide adjustment of the nozzles with the chain rail, the nozzles are formed in three sections, `above and below the web W: central upper and lower fixed sections 20 and 2l respectively, and pairs of upper and lower outer movable sections 22, 22 and 23, 23 respectively.

Air or other drying medium is supplied to the nozzles by upper and lower nozzle boxes 24 and 25 respectively which are connected to the exhaust port 26 of a fan 2.7. The drying medium is supplied to the fan 27 from the interior of the chamber lll through a heat exchanger or other medium conditioner Z8 in a fan oupola 29.

If desired, fresh drying medium may be supplied to the Y cupola 2.9, in which event the excess drying medium in the chamber is removed by an exhaust fan 31 having its inlet connected to the drying chamber lll adjacent the material inlet, for example, by a duct 32 having an adjustable damper 33 therein.

The upper and lower fixed nozzles 20 and 21 respectively each comprise spaced side walls 35, 35 which converge toward the web 'W, and endv walls 36, 36 to define' Patented `luly 14, 1959` therebetween a passage 37 for the drying medium from the associated nozzle box. The passage 37 is unobstructed across the full width of the xed nozzles to provide a uniform flow of drying medium therethrough. The upper and lower iixed nozzles are in registry with one another to provide uniform impingement of air against opposite sides of the cloth.

n accordance with the invention, the movable nozzles are positioned at opposite sides of the fixed nozzles for adjustment transversely of the web. As with the fixed nozzles, the upper and lower movable nozzles are mounted in registry with one another to prevent rippling of the cloth passing between the nozzles.

As shown in Fig. 9, each upper movable nozzle 22 comprises an elongated slide element 39 adapted to be slidably mounted on the nozzle box 24, for example, by guide rails 40, 40 (see Fig. 7). It is noted that guide members 40, 40 extend outwardly beyond the chain rails 11, 11 lto receive the elongated slide element 39. To provide a seal and a slide bearing between the slide element 39 and the guide members 40, 40, strips of asbestos or similar material are positioned as indicated at 4l, 41 between the guide members 40, 40 and the slide element 39. The slide `element terminates as indicated at 42 to provide access of the drying medium in the nozzle box to the interior of the nozzle 22 through an opening 43 provided in the nozzle box. The opening 43 is coextensive with the nozzle 22, and is in registry with the nozzle 22 when it is in its outer limit position, for eX- ample in the position shown at the right hand end of Fig. 2, and in broken lines in Fig. 4.

The nozzle 22 comprises downwardly converging side walls 45, 45 `closed at the opposite ends thereof by end plates 46, 46. Shown in Fig. 4, the end plates 46, 46 are in spaced parallel relation, and a plurality of partitions 47 are mounted intermediate the end plates 46, 46 at spaced intervals therebetween and parallel thereto. The lower movable nozzles 23 are constructed similarly to the nozzles 22 and similar reference numerals followed by the character a are applied to the corresponding parts. It is noted that the lower nozzles are slidably supported on the sealing strips 42a, 42a which are mounted between the slide element 39a and the nozzle box 25.

In accordance with the invention, means is provided interconnecting the slidable nozzles with the chain rails for adjustment therewith. To this end, the upper nozzle 22 is provided with an arm 50 mounted on the outer end plate 46. As shown in Fig. 4, the arm G clears the tenter element 13 as it travels along the chain rail 11. The arm 50 is connected to the chain rail 11 by an angle member 5l which is mounted for rotary adjustment on the chain rail 11 by means of a vertical Ibolt 52 and .bushing 53. vClearance is provided between the bushing 53 and the angle 51 to compensate for changes of longitudinal position of the bolt 52 relative to the iixed guide rails 40, 40 during angular adjustment of the chain rails 1-1, i1. Thus, when the rails ll, lll are adjusted toward and away from one another, the nozzles 22, 22 follow the adjustment so that the outer end plates 46 of the nozzles are always positioned inwardly of the tenter elements l?) and thus, may be positioned with a minimum clearance between the lower end of the nozzle 22 and the web W. Thus, in any rail position between maximum and minimum, the position of the slidable air nozzles is always constant relative to the selvage of the web W engaged by the elements 13.

The lower nozzle 23 is similarly mounted on the chain rail 1-1. To this end, the outer end plate 46a of the nozzle 23 is provided with an arm 55 which is connected to 'an angle member 56 on the chain rail 1l by means of a vertical bolt 57. The arm 55 is mounted for limited rotary and lateral adjustment on the arm angle member 56 by reason of the `loose t of a bushing 58 surrounding the vbolt 57 with the angle member 56.

vassess@ 4 Thus, the lower nozzle 23 also readily follows adjustment of the chain rail lll so that its nozzle opening is maintained in precise registry with the nozzle opening of the nozzle 22.

ln accordance with the invention, upon lateral adjustment of the slidable nozzles, the low area through the nozzle is correspondinglyV adjusted so that the impingement of air or other drying medium against web W is uniform across the full width of the web. The flow area of each movable nozzle extends from the end of the nozzle to the side rail. As shown in Fig. 4, the flow area of the nozzle is determined by the portions of the apertures 42 and 43 which are in registry. The slide element 39 of the nozzle covers that portion of the aperture 43 which is out of registry with the aperture 42, and the bottom wall of the nozzle box covers that portion of the aperture 42 which is out of registry with the aperture 43. The partitions 47 and 47a insure that the gaseous medium ilowing through the registering portions of the apertures 42 and 43 does not ilow inwardly from 'the selvage of the web W onto the portion of the web which is contacted by the medium flowing from the iixed nozzles. Escape of air between the nozzles 22 and the nozzle ybox 24 is precluded by sealing elements, preferably of asbestos material positioned between the nozzle box and the nozzle. One sealing element 60 is mounted on the inner end wall 46 of the nozzle 22 and bears against the bottom wall of the nozzle box 24. A similar sealing element is provided at 69a for the nozzle 23. At the outside of the nozzle box 24, a sealing element 61 is provided which bears against the slide element 39 to prevent escape of the air outwardly between the nozzle box and the slide element. A similar sealing element is provided at 61a for the lower nozzle 23.

To insure against excess drying in the areas where the movable nozzles overlap the fixed nozzles, bars are provided between the nozzle openings and the web W. These bars are mounted on the nozzle box and spaced regularly therefrom a distance corresponding to the vertical dirnension of the nozzle section, for example by welding to the fixed nozzles as shown in Fig. 1, so that the bar is disposed adjacent the opening of the movable nozzle with its outer edge in vertical alignment with the inner edge of the aperture for the movable nozzle. The bars for the upper movable nozzles 22 are indicated at 64 and the bars for the lower movable nozzles 23 are indicated at 65. As shown in Fig. 4, the bars 64 and 65 have a width corresponding to the spacing between the partitions 47 and 47a. This insures that at each point along the length of the dryer, a partition 47 overlies the bar 64 and a partition 47a underlies the bar 65. The outer edge of the bars 64 and 65 are disposed in precise alignment with the outer limit of the iixed nozzles 2@ and 2l. Thus, when the edges of the openings 43 and 43a intersect the space `between the partitions 47 and 47a, the bars 64 and 65 prevent the drying medium discharged through the nozzle openings 43 and 43a from being directed inwardly and overlapping the area which is dried by air from the `fixed nozzles.

By reason of the adjustment of the nozzle area of the movable nozzles, when drying narrow widths of web, the velocity of the drying medium expelled by the nozzles of the dryer is relatively large, and when drying wide webs, the velocity of the drying medium is lower, assuming a reasonably-constant output of the blower 27. Thus, when drying narrow webs, it is possible to run the chains i4, i4 at a faster rate, thereby enabling a faster lineal travel of material through the machine. Therefore, since narrow webs can be advanced to the machine at a faster rate, the drying rate of the web in pounds per hour may be approximately the same whether handling wide -webs or narrow webs.

Thus, the present invention provides a dryer which is readily adjustable to accommodate webs of diiering widths as well as webs which change in width from one end of the dryer to the other, and in -which the drying medium is impinged directly upon the web intermediate the selvages. Since none of the drying medium is directed beyond the selvages of the web, substantial saving in the drying medium yis obtained as well as elimination of the defect of conventional dryers in which the outer edges of the web dry more rapidly than the central portion. The present invention also enables the nozzle openings of the dryer to be set with minimum clearance between the web and the nozzle opening, thereby greatly increasing the drying eliiciency. Adjustment of the chain rails of the dryer automatically effects adjustment of the nozzles so that the position of the nozzles relative to the selvage of the web remains constant.

Wh-ile a particular embodiment or" the present invention has been herein illustrated and described, it is not intended to limit the invention to such disclosure, but changes and modifications may be made therein and thereto within the scope of the following claims.

I claim:

1. In a tenter dryer having spaced chain rails, means mounting said rails for relative transverse adjustment toward and away from one another, web engaging elements sl-idably mounted on said chain rail for engaging a web therebetween and conveying the same through said dryer, and at least one nozzle box substantially coextensive in length with said side chain rails spaced apart from the same for transporting drying medium for said dryer, said nozzle box having means delining a plurality of transversely disposed Ielongated apertures therein, at least one aperture extending outwardly closely adjacent the outermost adjusted position of one of said side chain rails, nozzle means in iiuid communication with said apertures having nozzle openings projecting intermediate said web engaging elements into close proximity to said web, said nozzle means including at least one movable section 'coextensive with said one aperture and mounted in registry with said aperture, means Slidably mounting said movable section for relative movement transverse to said side chain rails, means on said movable nozzle section operable upon inward adjustment of said movable nozzle section to block the portion of said aperture which extends outwardly beyond ythe inwardly adjusted position of said movable nozzle sections, to prevent outward iiow of drying medium beyond said nozzle section, a plurality of transversely-spaced vertical partitions in said nozzle section disposed longitudinally of said chain rails, and operable successively upon inward adjustment of said nozzle section to prevent flow of drying medium transversely inward beyond said aperture, and a bar having a lateral dimension corresponding to the spacing of said partitions, said bar being mounted on said nozzle box and spaced vertically therefrom a distance corresponding to the vertical dimension of said nozzle section so as to be disposed adjacent said opening of the movable nozzle with its outer edge in vertical alignment with the inner edge of said one aperture, whereby at least one of said partitions spans between said nozzle box and said bar to prevent flow of gaseous medium to said nozzles inwardly of the inner edge of said one aperture.

2. In a tenter dryer lhaving spaced chain rails, means mounting said rails for relative transverse adjustment toward and away from one another, web engagingR1 elements slidably mounted on said chain rail for engaging a web therebetween and conveying the same through said dryer, at least one nozzle box substantially coextensive in length with said s-ide chain rails spaced apart from .the same for transporting drying medium for said dryer, said nozzle -box extending substantially the full width between the outermost adjusted position of said web-engaging elements and having means defining a plurality of transversely disposed elongated apertures arranged in a plurality of series across 'the width of said nozzle box, each aperture being olset from the adjacent aperture of said series longitudinally of said dryer, said adjacent apertures being disposed in substantially diagonally abutting alignment whereby each series of apertures forms a passage yfor the drying medium coextensive in width with said nozzle box, nozzle means in fluid communication with each passage having nozzle openings projecting into close proximity to said web intermediate said web-engaging elements, each nozzle means comprising a series of nozzle sections respectively coextensive and in registry with said series of apertures, the outermost nozzle sections of each series being slidable transversely, a horizontally disposed slide element projecting outwardly from each movable nozzle section, coextensive in `width with the associated aperture, and operable upon inward adjustment of said movable nozzle section to cover only the portion of the associated aperture which extends beyond the inwardly adjusted position of said movable nozzle section, thereby to block flow of drying medium through the associated apertures outwardly beyond said nozzle sections, and means operable to block ow of drying medium through said nozzles inwardly beyond the associated apertures whereby diow of drying medium is coniined to the portions of said apertures and said nozzle sections which are in mutual registry.

3. A dryer according to claim 2 wherein said apertures are disposed in series of three and wherein further the central nozzle section of each series is fixed and is coextensive and in registry with the central aperture of said series.

4. A dryer according to claim 2 wherein said lastmentioned means comprises a plurality of transverselyspaced vertical partitions in each movable nozzle section disposed longitudinally of said chain rails, and a bar having a lateral dimension corresponding to the spacing of said partitions, said bar 'being mounted on said nozzle box and spaced vertically therefrom a distance corresponding to the vertical dimension of said movable nozzle section so as to be disposed adjacent the opening of the movable nozzle section with its outer edge in vertical alignment with the inner edge of the aperture associated with said movable nozzle section, whereby at least one of said partitions spans between said nozzle box and said bar to prevent now of gaseous medium through said nozzle sections inwardly of the edge of said associated apertures.

References Cited in the ile of this patent UNITED STATES PATENTS 184,550 Austria --...---.n Ian. 25, 1956 

